L'asthme de la mère, son niveau de contrôle et de sévérité pendant la grossesse et l'incidence d'asthme, de rhinite allergique et de dermatite atopique chez l'enfant

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal

Impact of type of drug insurance on adherence, persistence and costs of antidepressant drugs : a Quebec population-based study

Contexte: À date, il existe peu de données sur l’adhésion, la persistance et les coûts associés aux antidépresseurs selon le type d’assurance médicament (privé ou public). Objectif: Comparer selon le régime d’assurance médicament (privé ou public), l'adhésion, la persistance et les coûts des antidépresseurs. Méthodes de recherche: Une étude de cohorte appariée a été réalisée en utilisant des bases de données du Québec. Sujets: Nous avons sélectionné 194 patients assurés par un régime privé et 1923 patients assurés par le régime public de la Régie de l’assurance maladie du Québec (RAMQ) (18-64 ans) qui ont rempli au moins une ordonnance pour un antidépresseur entre décembre 2007 et septembre 2009. Mesures: L’adhésion, mesurée sur une période d’un an, a été estimée en utilisant le proportion of prescribed days covered (PPDC). Un modèle de régression linéaire a été utilisé afin d’estimer la différence moyenne en PPDC entre les patients assurés par un régime privé et ceux assurés par le régime public de la RAMQ. La persistance a été comparé entre ces deux groupes avec un modèle de régression de survie Cox, et le coût mensuel d'antidépresseurs ($ CAN) a été comparé entre ces deux groupes en utilisant un modèle de régression linéaire. Résultats: Le PPDC parmi les patients assurés par un régime privé était de 86,4% (intervalle de confiance (IC) 95%: 83,3%-89,5%) versus 81,3% (IC 95%: 80,1%-82,5%) pour les patients assurés par le régime public de la RAMQ, pour une différence moyenne ajustée de 6,7% (IC 95%: 3,0%-10,4%). La persistance après un an parmi les patients assurés par un régime privé était de 49,5% versus 18,9% pour les patients assurés par le régime public de la RAMQ (p <0,001), et le rapport de risque ajusté était de 0,48 (IC 95%: 0,30-0,76). Comparativement aux patients assurés par le régime public de la RAMQ, les patients ayant une assurance privée ont payé 14,94 $ CAD (95% CI: $12,30-$17,58) de plus par mois en moyenne pour leurs antidépresseurs. Conclusion: Les patients assurés par un régime privé avaient une meilleure adhésion, persistance, mais avaient aussi un plus haut coût pour leurs antidépresseurs que ceux assurés par le régime public de la RAMQ. Cette différence de coûts peut être due aux différentes exigences de paiement en pharmacie entre les deux régimes ainsi qu’aux limites des honoraires des pharmaciens imposés par le régime public.

La prise d’acide folique en période périconceptionnelle : une étude sur la concordance aux directives cliniques canadiennes et sur l’impact sur la prévalence des malformations congénitales au Québec

La prise d’un supplément d’acide folique en période préconceptionnelle réduit le risque d’une anomalie du tube neural (ATN), une malformation du système nerveux. Dans le but d’en réduire la prévalence, la Société des Obstétriciens et Gynécologues du Canada a émis de nouvelles directives cliniques en 2007 qui tenaient compte de différents facteurs de risque pour les ATN et pour qui la dose recommandée variait selon le profil de risque de la femme, allant de 0,4 à 5,0 mg d’acide folique. Jusqu’à présent, peu de données sont disponibles sur les effets de la prise d’une haute dose d’acide folique. Les objectifs de cette étude étaient: 1) d’évaluer la concordance entre la supplémentation en acide folique chez les femmes enceintes et les nouvelles recommandations canadiennes; 2) d’identifier les déterminants d’une utilisation concordante et 3) d’évaluer si la prise de hautes doses d’acide folique en période périconceptionnelle réduisait le risque de malformations congénitales autre que les ATN. Pour répondre à ces objectifs, une étude transversale et une étude écologique ont été effectuées. La première incluait 361 femmes enceintes recrutées aux cliniques d’obstétriques du CHU Sainte-Justine et la deuxième utilisait le Registre Québécois des Grossesses, issu du jumelage de trois banques de données administratives au Québec (RAMQ, Med-Écho et ISQ), où 152 392 couples mère-enfant ont été identifiés. Seul 27% des femmes enceintes ayant participé à l’étude transversale avaient une supplémentation en acide folique, avec ou sans ordonnance, concordante aux lignes directrices canadiennes. La concordance variait selon leur profil de facteurs de risque pour les ATN. Notre étude écologique montre que la prévalence annuelle de l’utilisation de haute dose d’acide folique (avec ordonnance) en période périconceptionnelle a augmenté de 0,17% à 0,80% (p < 0,0001) entre 1998 et 2008 et que la prévalence des malformations congénitales majeures a augmenté de 15% au cours de la même période (3,35% à 3,87%, p<0,0001). Les résultats de nos deux études montrent que l’acide folique n’est pas largement utilisé par les femmes en âge de procréer et ce, peu importe la dose. De nouvelles campagnes de santé publique devront être mises sur pied, afin d’inciter les femmes à consommer de l’acide folique avant et pendant leur grossesse. Également, la prise de haute dose d’acide folique ne semble pas avoir diminué le risque de malformations congénitales, à l’échelle populationnelle.

Using clinical trial data and linked administrative health data to reduce the risk of adverse events associated with the uptake of newly released drugs by older Australians : a model process

Background
The study was undertaken to evaluate the contribution of a process which uses clinical trial data plus linked de-identified administrative health data to forecast potential risk of adverse events associated with the use of newly released drugs by older Australian patients.

Methods
The study uses publicly available data from the clinical trials of a newly released drug to ascertain which patient age groups, gender, comorbidities and co-medications were excluded in the trials. It then uses linked de-identified hospital morbidity and medications dispensing data to investigate the comorbidities and co-medications of patients who suffer from the target morbidity of the new drug and who are the likely target population for the drug. The clinical trial information and the linked morbidity and medication data are compared to assess which patient groups could potentially be at risk of an adverse event associated with use of the new drug.

Results
Applying the model in a retrospective real-world scenario identified that the majority of the sample group of Australian patients aged 65 years and over with the target morbidity of the newly released COX-2-selective NSAID rofecoxib also suffered from a major morbidity excluded in the trials of that drug, indicating a substantial potential risk of adverse events amongst those patients. This risk was borne out in post-release morbidity and mortality associated with use of that drug.

Conclusions
Clinical trial data and linked administrative health data can together support a prospective assessment of patient groups who could be at risk of an adverse event if they are prescribed a newly released drug in the context of their age, gender, comorbidities and/or co-medications. Communication of this independent risk information to prescribers has the potential to reduce adverse events in the period after the release of the new drug, which is when the risk is greatest.

Note: The terms 'adverse drug reaction' and 'adverse drug event' have come to be used interchangeably in the current literature. For consistency, the authors have chosen to use the wider term 'adverse drug event' (ADE).

Using clinical trial data and linked administrative health data to reduce the risk of adverse events associated with the uptake of newly released drugs by older Australians: a model process

BACKGROUND: The study was undertaken to evaluate the contribution of a process which uses clinical trial data plus linked de-identified administrative health data to forecast potential risk of adverse events associated with the use of newly released drugs by older Australian patients. METHODS: The study uses publicly available data from the clinical trials of a newly released drug to ascertain which patient age groups, gender, comorbidities and co-medications were excluded in the trials. It then uses linked de-identified hospital morbidity and medications dispensing data to investigate the comorbidities and co-medications of patients who suffer from the target morbidity of the new drug and who are the likely target population for the drug. The clinical trial information and the linked morbidity and medication data are compared to assess which patient groups could potentially be at risk of an adverse event associated with use of the new drug. RESULTS: Applying the model in a retrospective real-world scenario identified that the majority of the sample group of Australian patients aged 65 years and over with the target morbidity of the newly released COX-2-selective NSAID rofecoxib also suffered from a major morbidity excluded in the trials of that drug, indicating a substantial potential risk of adverse events amongst those patients. This risk was borne out in post-release morbidity and mortality associated with use of that drug. CONCLUSIONS: Clinical trial data and linked administrative health data can together support a prospective assessment of patient groups who could be at risk of an adverse event if they are prescribed a newly released drug in the context of their age, gender, comorbidities and/or co-medications. Communication of this independent risk information to prescribers has the potential to reduce adverse events in the period after the release of the new drug, which is when the risk is greatest.Note: The terms 'adverse drug reaction' and 'adverse drug event' have come to be used interchangeably in the current literature. For consistency, the authors have chosen to use the wider term 'adverse drug event' (ADE).

Comparing subjective and objective measures of health : Evidence from hypertension for the income/health gradient

Economists rely heavily on self-reported measures to examine the relationship between income and health. We directly compare survey responses of a self-reported measure of health that is commonly used in nationally representative surveys with objective measures of the same health condition. We focus on hypertension. We find no evidence of an income/health greadient using self-reported hypertension but a sizeable gradient when using objectively measured hypertension. We also find that the probability of a false negative reporting is significantly income graded. Our results suggest that using commonly available self-reported chronic health measures might underestimate true income-related inequalities in health.

The causal effect of income on health: Evidence from German reunification

We investigate whether therewas a causal effect of income changes on the health satisfaction of East and West Germans in the years following reunification. Our data source is the German Socio-Economic Panel (GSOEP) between 1984 and 2002, and we fit a recently proposed fixed-effects ordinal estimator to our health measures and use a causal decomposition technique to account for panel attrition.We find evidence of a significant positive effect of income changes on health satisfaction, but the quantitative size of this effect is small. This is the case with respect to current income and a measure of ‘permanent’ income.

Health risk from the use of roof-harvested rainwater in Southeast Queensland, Australia, as potable or nonpotable water, determined using quantitative microbial risk assessment

A total of 214 rainwater samples from 82 tanks were collected in urban Southeast Queensland (SEQ) in Australia and analysed for the zoonotic bacterial and protozoan pathogen using real-time binary PCR and quantitative PCR (qPCR). Quantitative Microbial Risk Assessment (QMRA) analysis was used to quantify the risk of infection associated with the exposure to potential pathogens from potable and non-potable uses of roof-harvested rainwater. Of the 214 samples tested, 10.7%, 9.8%, and 5.6%, and 0.4% samples were positive for Salmonella invA, Giardia lamblia β-giardin , Legionella pneumophila mip, and Campylobacter jejuni mapA genes. Cryptosporidium parvum could not be detected. The estimated numbers of viable Salmonella spp., G. lamblia β-giradin, and L. pneumophila genes ranged from 1.6 × 101 to 9.5 × 101 cells, 1.4 × 10-1 to 9.0 × 10-1 cysts, and 1.5 × 101 to 4.3 × 101 per 1000 ml of water, respectively. Six risk scenarios were considered from exposure to Salmonella spp., G. lamblia and L. pneumophila. For Salmonella spp., and G. lamblia, these scenarios were: (1) liquid ingestion due to drinking of rainwater on a daily basis (2) accidental liquid ingestion due to garden hosing twice a week (3) aerosol ingestion due to showering on a daily basis, and (4) aerosol ingestion due to hosing twice a week. For L. pneumophila, these scenarios were: (5) aerosol inhalation due to showering on a daily basis, and (6) aerosol inhalation due to hosing twice a week. The risk of infection from Salmonella spp., G. lamblia, and L. pneumophila associated with the use of rainwater for showering and garden hosing was calculated to be well below the threshold value of one extra infection per 10,000 persons per year in urban SEQ. However, the risk of infection from ingesting Salmonella spp. and G. lamblia via drinking exceeds this threshold value, and indicates that if undisinfected rainwater were ingested by drinking, then the gastrointestinal diseases of Salmonellosis and Giardiasis is expected to range from 5.0 × 100 to 2.8 × 101 (Salmonellosis) and 1.0 × 101 to 6.4 × 101 (Giardiasis) cases per 10,000 persons per year, respectively. Since this health risk seems higher than that expected from the reported incidences of gastroenteritis, the assumptions used to estimate these infection risks are critically examined. Nonetheless, it would seem prudent to disinfect rainwater for potable use.

Reproductive health : findings from the Australian Longitudinal Study on Women’s Health. Chapter 3: Use of contraception

Chapter 3: Use of contraception. p15-32 Key findings: This section examines trends in the use of contraception between 1996 and 2006 by women who participated in the surveys for the 1973-1978 cohort of the Australian Longitudinal Study on Women’s Health. 1. The oral contraceptive pill was the most commonly used method of contraception at each survey, but its use decreased over time. 2.Of women who consistently used contraception, 40% used the oral contraceptive pill as their only method of contraception in at least three out of four surveys. 3. The proportion of women using condoms as their only method of contraception remained steady over time (15-18%) but only 3% of all women used condoms only at every survey. 4. The proportion of women using both condoms and the oral contraceptive pill remained steady at 13-14% of all women from Survey 1 to 3, but decreased to 8% of all women at Survey 4. 5. The use of methods other than the oral contraceptive pill and/or condoms increased at Survey 4. 6. The proportion of women using an implant (e.g. Implanon) remained steady between Surveys 3 and 4, with 3% of women using an implant only. Around one third of implant users at Survey 3 continued to use this method at Survey 4. 7. The main reasons for not using contraception at Surveys 3 and 4 were pregnancy, trying to conceive, or no male sexual partners. 8. Women who used contraception were more likely to be in de facto relationships or single, be up to date with Pap tests and have had two or more births. 9. Women who did not use contraception were more likely to be non-drinkers and/or do low levels of exercise, have had one birth and have experienced miscarriage. 10. Contraception changed in expected ways according to reproductive events: women who reported only miscarriages between surveys also stopped using contraception in the same period; most women who did not report reproductive events continued to use the same method of contraception; and women who had a termination tended to switch methods.

Reproductive health: findings from the Australian Longitudinal Study on Women’s Health. Chapter 5: fertility and infertility

Chapter 5: Fertility and infertility. p52-70. This section describes patterns of fertility across Surveys 1 to 4 among the cohort of women who were born in 1973-1978. This section includes the examination of pregnancy outcomes including both live births and pregnancy losses (stillbirths, miscarriages, terminations and ectopic pregnancies). This section also examines the prevalence of self-reported problems with fertility and whether these women sought advice and/or treatment. As women age they are more likely to experience infertility and, with little other data available, the ALSWH provides an important opportunity to examine this problem and the related use of health services. 1. Pregnancy losses are common. Half of the women who report a pregnancy outcome at Survey 4 have experienced a pregnancy loss. 2. More than one third (39%) of women who have experienced a live birth by Survey 4 have also experienced a pregnancy loss. 3. For every ten women aged 28-33 years in 2006: four women had not had been pregnant, five women had a live birth (with or without a recognised pregnancy loss), and one woman had a recognised pregnancy loss only. 4. Among women who had tried to conceive or had been pregnant, one-in-six had experienced infertility. (i.e. tried unsuccessfully to get pregnant for 12 months or more) 5. The most significant factors associated with having infertility, seeking advice and using treatment were: polycystic ovary syndrome, endometriosis and miscarriage. 6. Of the women who reported infertility, two-thirds sought advice but only half used treatment. 7. Most of the women who used fertility treatment had used low cost and non-invasive methods.

Tackling the health burden from household air pollution (HAP) : development and implementation of new WHO Guidelines

Household air pollution (HAP), arising mainly from the combustion of solid and other polluting fuels, is responsible for a very substantial public health burden, most recently estimated as causing 3.5 million premature deaths in 2010. These patterns of household fuel use have also important negative impacts on safety, prospects for poverty reduction and the environment, including climate change. Building on previous air quality guidelines, the WHO is developing new guidelines focused on household fuel combustion, covering cooking, heating and lighting, and although global, the key focus is low and middle income countries reflecting the distribution of disease burden. As discussed in this paper, currently in development, the guidelines will include reviews of a wide range of evidence including fuel use in homes, emissions from stoves and lighting, household air pollution and exposure levels experienced by populations, health risks, impacts of interventions on HAP and exposure, and also key factors influencing sustainable and equitable adoption of improved stoves and cleaner fuels. GRADE, the standard method used for guidelines evidence review may not be well suited to the variety and nature of evidence required for this project, and a modified approach is being developed and tested. Work on the guidelines is being carried out in close collaboration with the UN Foundation Global Alliance on Clean cookstoves, allowing alignment with specific tools including recently developed international voluntary standards for stoves, and the development of country action plans. Following publication, WHO plans to work closely with a number of countries to learn from implementation efforts, in order to further strengthen support and guidance. A case study on the situation and policy actions to date in Bhutan provide an illustration of the challenges and opportunities involved, and the timely importance of the new guidelines and associated research, evaluation and policy development agendas.

Data warehousing model for integrating fragmented electronic health records from disparate and heterogeneous clinical data stores

This research was a step forward in developing a data integration framework for Electronic Health Records. The outcome of the research is a conceptual and logical Data Warehousing model for integrating Cardiac Surgery electronic data records. This thesis investigated the main obstacles for the healthcare data integration and proposes a data warehousing model suitable for integrating fragmented data in a Cardiac Surgery Unit.

Common values in assessing health outcomes from disease and injury: Disability weights measurement study for the Global Burden of Disease Study 2010

BACKGROUND Measurement of the global burden of disease with disability-adjusted life-years (DALYs) requires disability weights that quantify health losses for all non-fatal consequences of disease and injury. There has been extensive debate about a range of conceptual and methodological issues concerning the definition and measurement of these weights. Our primary objective was a comprehensive re-estimation of disability weights for the Global Burden of Disease Study 2010 through a large-scale empirical investigation in which judgments about health losses associated with many causes of disease and injury were elicited from the general public in diverse communities through a new, standardised approach. METHODS We surveyed respondents in two ways: household surveys of adults aged 18 years or older (face-to-face interviews in Bangladesh, Indonesia, Peru, and Tanzania; telephone interviews in the USA) between Oct 28, 2009, and June 23, 2010; and an open-access web-based survey between July 26, 2010, and May 16, 2011. The surveys used paired comparison questions, in which respondents considered two hypothetical individuals with different, randomly selected health states and indicated which person they regarded as healthier. The web survey added questions about population health equivalence, which compared the overall health benefits of different life-saving or disease-prevention programmes. We analysed paired comparison responses with probit regression analysis on all 220 unique states in the study. We used results from the population health equivalence responses to anchor the results from the paired comparisons on the disability weight scale from 0 (implying no loss of health) to 1 (implying a health loss equivalent to death). Additionally, we compared new disability weights with those used in WHO's most recent update of the Global Burden of Disease Study for 2004. FINDINGS 13,902 individuals participated in household surveys and 16,328 in the web survey. Analysis of paired comparison responses indicated a high degree of consistency across surveys: correlations between individual survey results and results from analysis of the pooled dataset were 0·9 or higher in all surveys except in Bangladesh (r=0·75). Most of the 220 disability weights were located on the mild end of the severity scale, with 58 (26%) having weights below 0·05. Five (11%) states had weights below 0·01, such as mild anaemia, mild hearing or vision loss, and secondary infertility. The health states with the highest disability weights were acute schizophrenia (0·76) and severe multiple sclerosis (0·71). We identified a broad pattern of agreement between the old and new weights (r=0·70), particularly in the moderate-to-severe range. However, in the mild range below 0·2, many states had significantly lower weights in our study than previously. INTERPRETATION This study represents the most extensive empirical effort as yet to measure disability weights. By contrast with the popular hypothesis that disability assessments vary widely across samples with different cultural environments, we have reported strong evidence of highly consistent results.